Such a throttle valve apparatus can serve for the metered feeding of an air-fuel mixture to an internal combustion engine, which for example controlled via an electronic device, receives fuel fed into the intake pipe corresponding to the respective throttle valve angle, which is then fed to the internal combustion engine. In the case of such an internal combustion engine operating with intake pipe injection, the power output by the internal combustion engine is thus controlled via the throttle valve in that the fed-in quantity of air-fuel mixture is influenced by means of the throttle valve in that the cross section in the intake pipe through which a flow can flow is changed relative to the through-flow cross section by the angular position of the throttle valve.
In the case of an internal combustion engine with injection of the fuel directly into a working cylinder of the internal combustion engine, the quantity of combustion air fed into the internal combustion engine is influenced via the throttle valve, again via a change of the angular position of the throttle valve relative to the through-flow cross section in the intake pipe.
When an internal combustion engine that is not yet at normal operating temperature is started, the power to be output by the internal combustion engine for bringing about stable idling is higher than at normal operating temperature, since in the cold state the frictional torque of the internal combustion engine is higher than in the state at operating temperature. This can be offset with an idle rotational speed of the internal combustion engine that is elevated in cold starting mode.
In the case of a known internal combustion engine operating with a carburettor for fuel atomisation, the air-fuel mixture for this purpose was enriched by way of throttling the quantity of intake air to be fed in via the main intake air duct.
By way of DE 79 08 299 U1, an automatically resetting starting carburettor to a main carburettor has become known, in the case of which for initiating the starting process a starting slide is brought into a raised position by means of an actuating part and the starting slide via a pawl held in this position until after termination of the starting process the user of the engine renders the main carburettor operational through initial actuation of the main gas slide, the starting carburettor thereby being automatically put out of service.
By way of DE 39 26 424 A1, a throttle valve for an internal combustion engine has become known, which is actuated via an electric motor. When by a control device activating the electric motor an emergency is detected, during which the throttle valve could close up to an opening angle of 0 degree, i.e. the internal combustion engine would no longer be supplied with air-fuel mixture, the throttle valve is held in an opening position via a stop pin, which is extended by an hydraulically actuated stop actuator, so that the internal combustion engine can be continuously supplied with an air-fuel mixture and idling of the internal combustion engine thereby being ensured.
By means of US 2006/0005808 A1 a throttle valve for a motor cycle has become known, which is actuated by the user of the motor cycle via a control cable. In addition to the control cable actuation, the throttle valve can be additionally actuated by an electrically driven actuator, which overrides the manual actuation of the throttle valve when by an electronic control device of the motor cycle it is detected that the motor cycle is in a special operating mode. The special operating mode can be a passing mode of the motor cycle, during which the same is accelerated with a predetermined acceleration for measuring the noise emissions of the motor cycle. In such a state, the electrically driven actuator then reduces the opening angle of the throttle valve in order to reduce the power output by the internal combustion engine of the motor cycle, thereby reducing the noise emissions.
In particular in the case of competition motor cycles it is important to keep the dead weight of the vehicle low, which is why such vehicles are often equipped with a control cable-actuated throttle valve, i.e. an electric motor for actuating the throttle valve is omitted. In the case of a known motor cycle operating with fuel injection with control cable-actuated throttle valve, a bypass system for the cold starting mode of the internal combustion engine is provided and the bypass can be opened or closed for cold starting operation by the driver of the motor cycle.
However, this system has the disadvantage that the idle speed control via the bypass distorts the map (manifold pressure signal) sensor signal and an electronic control device (ECU, engine control unit) provided for the control of the internal combustion engine uses the distorted sensor signal for determining the fuel quantity to be injected. In addition, the ECU cannot detect the change of the idle air performed by the driver and makes available an unchanged quantity of fuel although more or less idle air is fed in through the bypass. This results in that the raw emission values of the internal combustion engines increase and no stable idling in cold starting mode is achieved.
When the fuel injection system is operated in cold starting mode, the bypass is open so that during the opening of the throttle valve the vacuum that is present in the bypass drops, as a result of which the flow of air through the bypass is reduced and a transition region is created that can only be matched with difficulty which results in that the response behaviour of the internal combustion engine deteriorates and differs from the response behaviour in the case of an internal combustion engine at operating temperature. This in turn results in that the driver, which expects spontaneous and stable response behaviour of the internal combustion engine, frequently warms up the internal combustion engine in the stationary state by specifically revving up the engine until it has reached the normal operating temperature.